This invention pertains to a catalytic composition for use in hydrocracking processes to maximize middle distillate yield from hydrocarbons boiling above about 650.degree. F., which composition comprises an alumina-zeolite support, a rare earth exchange metal component, at least one metal component selected from Group VIB or Group VIII and from about 0.1 to about 5 wt. % of at least one component selected from Group IIA based on the weight of the finished catalyst. A considerable number of materials have been heretofore proposed as catalysts for hydrocracking hydrocarbon oils. In the past few years much attention has been devoted to using crystalline aluminosilicates as an element in such hydrocracking catalysts. In general, the crystalline aluminosilicates are used in combination with a porous matrix such as silica-alumina. In some cases the co-catalytic activity of the crystalline aluminosilicate material and the acidic porous matrix with various metallic promoters has been found to be an effective catalyst material.